package com.alibaba.cloud.utils;

import jakarta.servlet.http.HttpServletRequest;

/**
 * The Class NetworkUtil.
 */
public class NetworkUtil {

    /**
     * Gets the ip addr.
     *
     * @param request the request
     * @return String
     * @MethodName: getIpAddr
     * @Description: ip 地址获取
     *               获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     *               可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     * @Author: zhb1316783262@163.com
     * @Date: 2019年2月19日下午12:02:49
     */
    protected String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if (ip.indexOf(",") != -1) {
                ip = ip.split(",")[0];
            }
        }
        return ip;
    }
}
